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TECH DETAILS: 2021 KTM Motocross Range | News

KTM's 2021 motocross models feature a range of upgrades focused on improving the performance of the current, championship-winning platform.

Improvements for 2021 across the full-size range focus on suspension and chassis modifications, tweaks to engine architecture to further enhance reliability, new Dunlop tires and a reworked graphics aesthetic. The WP XACT front forks and rear shocks have been overhauled with new components as well as being reconfigured with a slightly firmer standard setting to increase confidence and comfort across a wider spread of surfaces.

As the flagship model in the 4-stroke range, the KTM 450 SX-F benefits from modifications to the piston, crankshaft, engine casing, rocker arms and shift locker to further hike the bike’s excellent reliability, shave more weight and aid practicality in terms of general maintenance.

In addition, the 2021 KTM 450 SX-F together with the new KTM 350 SX-F and KTM 250 SX-F machines can connect with the advanced myKTM app using an extra Connectivity Unit kit – available in the KTM PowerParts catalog. With the bar-pad-integrated Connectivity Unit fitted and the myKTM app installed, riders can personalize their KTM SX-F according to their preferences and track conditions without technical assistance. Offering the finest technical touch, the myKTM app allows for a wide spectrum of adjustability on the fly, a privilege that was limited to elite KTM factory riders until recently.

The 2021 KTM 125 SX is boldened with a fresh piston and clutch internals, with the treatment extending to the 250 cc-bothering KTM 150 SX.

KTM treats its Sportminicycle roster with the same ground-up priority for development as the full-size bikes. The KTM 85 SX, KTM 65 SX and KTM 50 SX & KTM 50 SX MINI therefore count on a new throttle assembly for better and smoother throttle action. For the KTM 85 SX, braking potential is much higher thanks to larger discs and a completely new front and rear brake system made by FORMULA. All three junior motocrossers now have a tapered handlebar allowing fitment of ODI lock-on grips. For the KTM 50 SX and KTM 50 SX MINI, the new tapered handlebar allows fitment of thinner grips.

“The development work never stops for our engineers here in Mattighofen or over in the USA. Gathering feedback from top-level Motocross and Supercross racers from every part of the world, for model year 2021 we are proud to introduce the most technically advanced line-up of motocrossers on the market. Class leaders in terms of performance, the 2021 models enjoy detailed refinements combined with updated racy looks across the range. For 2021, we are very pleased to introduce the myKTM app for all 4-stroke models, an advanced tool designed to help riders get the best out of their potential,” confirmed KTM´s Product Manager Offroad, Joachim Sauer.

New Features for 2021

2021 KTM 450 SX-F

  • NEW graphics with updated color scheme.
  • NEW mapping increases low-end power and includes split injection for better fuel atomization and punch throughout the rev range. Map 2 has also been enhanced for the most extreme performance option.
  • NEW connecting rod with upper copper-beryllium bushing that reduces friction for free-revving engine character and improved durability.
  • Reworked shift locker for improved durability.
  • NEW hour meter casing with additional fixing points and only two M6 screw dimensions (only 2 sizes for entire casing for easy servicing).
  • UPDATED WP XACT front forks with new internals—designed for refined performance, comfort and handling—feature extended oil and air bypasses to reduce pressure peaks while a new mid-valve damping system improves damping control.
  • Performing in concert with the new air bypass, a smaller rebound spacer in the air leg increases air volume in the negative chamber for a more linear spring curve, emulating the behavior of a spring while keeping all the benefits of an air fork.
  • Reworked WP XACT shock with a new o-ring for the link piston to reduce fading and improve consistency over long motos.
  • NEW suspension settings front and rear complement the new hardware for better traction.
  • NEW “low-friction” linkage bearing seals made by SKF provide noticeably freer linkage action.
  • NEW Dunlop MX33 tyres.

2021 KTM 350 SX-F and 250 SX-F

  • NEW graphics with updated color scheme.
  • UPDATED WP XACT front forks with new internals—designed for refined performance, comfort and handling—feature extended oil and air bypasses to reduce pressure peaks while a new mid-valve damping system improves damping control.
  • Performing in concert with the new air bypass, a smaller rebound spacer in the air leg increases air volume in the negative chamber for a more linear spring curve, emulating the behavior of a spring while keeping all the benefits of an air fork.
  • Reworked WP XACT shock with a new o-ring for the link piston to reduce fading and improve consistency over long motos.
  • NEW suspension settings front and rear complement the new hardware for better traction.
  • NEW “low-friction” linkage bearing seals made by SKF provide noticeably freer linkage action.
  • NEW Dunlop MX33 tyres.

2021 KTM 250 SX Highlights

  • NEW graphics with updated color scheme.
  • NEW throttle assembly with roller actuation delivers smoother throttle motion and improved cable life.
  • UPDATED WP XACT front forks with new internals—designed for refined performance, comfort and handling—feature extended oil and air bypasses to reduce pressure peaks while a new mid-valve damping system improves damping control.
  • Performing in concert with the new air bypass, a smaller rebound spacer in the air leg increases air volume in the negative chamber for a more linear spring curve, emulating the behavior of a spring while keeping all the benefits of an air fork
  • Reworked WP XACT shock with a new o-ring for the link piston to reduce fading and improve consistency over long motos.
  • NEW suspension settings front and rear complement the new hardware for better traction.
  • NEW “low-friction” linkage bearing seals made by SKF provide noticeably freer linkage action, offering better suspension feel and performance throughout the shock stroke.
  • NEW Dunlop MX33 tyres.

2021 KTM 150SX and 125SX Highlights

  • NEW piston.
  • NEW thicker inner clutch hub sleeves for even better durability.
  • NEW Dunlop MX33 tyres.
  • NEW “low-friction” linkage bearing seals made by SKF provide noticeably freer linkage action, offering better suspension feel and performance throughout the shock stroke.
  • NEW suspension settings front and rear compliment the new hardware for better traction.
  • Reworked WP XACT shock with a new o-ring for the link piston to reduce fading and improve consistency over long motos.
  • Performing in concert with the new air bypass, a smaller rebound spacer in the air leg increases air volume in the negative chamber for a more linear spring curve, emulating the behavior of a spring while keeping all the benefits of an air fork.
  • UPDATED WP XACT front forks with new internals—designed for refined performance, comfort and handling—feature extended oil and air bypasses to reduce pressure peaks while a new mid-valve damping system improves damping control.
  • NEW throttle assembly with roller actuation delivers smoother throttle motion and improved cable life.
  • NEW graphics with updated color scheme.

2021 KTM 85 SX Highlights

  • NEW graphics to match the look of the full-sized SX range.
  • NEW FORMULA brakes featuring a 2-piston floating front caliper and a single-piston floating rear with dimensions close to full-size SX brakes (pads interchange from the full-size SX model) provide improved braking power and feel and more consistent brake pad wear.
  • NEW larger rear brake disc (220 mm instead of 210 mm).
  • NEW rear hub adapted to the new disc and new fork boot adapted to the new brake caliper.
  • NEW throttle assembly with roller actuation delivers smoother throttle motion and improved cable life.
  • NEW throttle cable with improved fixation to the carburetor throttle cover.
  • NEW clutch master cylinder design to match the new brake master cylinder.

2021 KTM 65 SX Highlights

  • NEW graphics to match the READY TO RACE look of the full-sized SX range.
  • NEW WP XACT 35 mm air-sprung front forks are incredibly light and feature thinner outer tubes to deliver a 260 gram weight reduction for agile, confidence-inspiring handling.
  • Reworked triple clamps designed to accommodate the new fork diameter.
  • NEW tapered handlebars (Ø 28/22 mm) provide improved feel and comfort and include new ODI lock-on grips, just like full-size SX models, and a new handlebar pad with KTM logo.
  • NEW throttle assembly with roller actuation delivers smoother throttle motion and improved cable life.
  • NEW throttle cable with improved fixation to the carburetor throttle cover.

2021 KTM 50 SX Highlights

  • NEW graphics to match the READY TO RACE look of the full-sized SX range.
  • NEW WP XACT 35 mm air-sprung fork is ultra-lightweight and easily adjustable for different rider sizes and track conditions and features thinner outer tubes to deliver a 240 gram weight reduction for agile, confidence-inspiring handling.
  • Adjustable WP XACT rear suspension with PDS (Progressive Damping System) technology has been reworked with new settings to match the performance of the WP XACT fork.
  • Reworked triple clamps designed to accommodate the new fork diameter.
  • NEW tapered aluminum handlebar (Ø 28/22/18 mm) provides improved control and comfort thanks to increased flex and a smaller end diameter. A new handlebar pad with KTM logo is included.
  • NEW handlebar grips (ODI lock-on) with decreased diameter to provide increased control, comfort and confidence for smaller hands.
  • NEW throttle assembly with roller actuation delivers smoother throttle motion and improved cable life.
  • NEW throttle cable with improved fixation to the carburetor throttle cover.

The 2021 KTM SX range will become available at KTM dealers from June 2020 onwards.